Field of the Invention
This invention relates to centrifuge apparatus and, in particular, to a centrifuge rotor having a retaining arrangement thereon which prevents the escape of a tube carrier from the rotor.
Centrifuge apparatus are known which are adapted especially for the centrifugation of samples of material carried in test tubes or in small capped, plastic vials known as micro test tubes or microtubes. Exemplary of such apparatus are those described in U.S. Pat. Nos. 4,375,272 (Sutton), 4,341,342 (Hara), 4,306,676 (Edwards et al.) and 3,059,239 (Williams). The last-mentioned Williams patent discloses a generally cylindrical rotor body having angularly adjacent arms which cooperate to define peripheral grooves. The grooves extend generally parallel to the rotor'Is axis of rotation. Confronting faces on the arms are provided with slots which enable each of the peripheral grooves to receive and support a tube carrier. In the Williams patent each tube carrier is an elongated rectangular member having an array of appertures arranged therein. The appertures are sized to receive and to hold a corresponding plurality of microtubes. When a loaded tube carrier is inserted into confronting peripheral slots on the rotor, the carrier is edgewise supported in the groove such that the axis of each tube carried by the carrier extends substantially radially outwardly with respect to the body of the rotor.
It is possible that during centrifugation individual ones of the tubes carried on a tube carrier may burst. As a result the rotor may become unbalanced and wobble about its axis of rotation. Such an occurrence has been observed to impose lifting forces on the tube carriers supported within the peripheral grooves of the rotor. The carriers, therefore, have a tendency to be lifted up and out of the peripheral grooves in the rotor. In extreme cases centrifugal force effects have been observed literally to bend the uplifted portion of the tube carrier radially outwardly.
In view of the foregoing, it is believed advantageous to provide a retaining arrangement for a centrifuge rotor which will effectively prevent the escape of a tube carrier from a peripheral groove formed in the rotor body in the event of rotor unbalance.